@article{10902/18394,
year = {2019},
month = {4},
url = {http://hdl.handle.net/10902/18394},
abstract = {Signals consistent with the B+c(2S) and B*+c(2S) states are observed in proton-proton collisions at √s=13  TeV, in an event sample corresponding to an integrated luminosity of 143  fb−1, collected by the CMS experiment during the 2015–2018 LHC running periods. These excited ¯bc states are observed in the B+cπ+π− invariant mass spectrum, with the ground state B+c reconstructed through its decay to J/ψπ+. The two states are reconstructed as two well-resolved peaks, separated in mass by 29.1±1.5(stat)±0.7(syst)  MeV. The observation of two peaks, rather than one, is established with a significance exceeding five standard deviations. The mass of the B+c(2S) meson is measured to be 6871.0±1.2(stat)±0.8(syst)±0.8(B+c)  MeV, where the last term corresponds to the uncertainty in the world-average B+c mass.},
publisher = {American Physical Society},
publisher = {Phys. Rev. Lett. 122, 132001 (2019)},
title = {Observation of Two Excited B+c States and Measurement of the B+c(2S) Mass in pp Collisions at √s=13  TeV},
author = {Sirunyan, A. M. and Cabrillo Bartolomé, José Iban and Calderón Tazón, Alicia and Chazín Quero, Bárbara and Duarte Campderros, Jorge and Fernández García, Marcos and Fernández Manteca, Pedro José and García Alonso, Andrea and Gómez Gramuglio, Gervasio and Martínez Rivero, Celso and Martínez Ruiz del Árbol, Pablo and Matorras Weinig, Francisco and Piedra Gómez, Jonatan and Prieëls, Cédric and Rodrigo Anoro, Teresa and Ruiz Jimeno, Alberto and Scodellaro, Luca and Trevisani, Nicolo and Vila Álvarez, Iván },
}